12 November 2013 EMA/HMPC/342334/2013 Committee on Herbal Medicinal Products (HMPC) Assessment report on Thymus vulgaris L., vulgaris zygis L., herba Based on Article 16d(1), Article 16f and Article 16h of Directive 2001/83/EC as amended (traditional use) Final Herbal substance(s) (binomial scientific name of the plant, including plant part) Thymus vulgaris L., Thymus zygis L., herba Herbal preparation(s) a) Liquid extract (DER 1:1), extraction solvent ethanol 24% (v/v) Pharmaceutical forms Rapporteur Assessor(s) b) Liquid extract (DER 1:1.16), extraction solvent glycerol 85% (m/m): ethanol 25% (m/m) (0.1:2) c) Liquid extract (DER 1:2-2.5), extraction solvent ammonia solution 10% (m/m) : glycerol 85% (m/m) : ethanol 90% (v/v) : water (1:20:70:109) d) Tincture (1:10), extraction solvent ethanol 70% (v/v) e) Tincture (1:5), extraction solvent ethanol 70% (v/v) f) Soft extract (DER 5-8:1), extraction solvent ethanol 25% - 30% (v/v) g) Liquid extract fresh herb (DER 1:1.5-2.4), extraction solvent water h) Dry extract (DER 6-10:1), extraction solvent ethanol 70% (v/v) i) Dry extract (DER 1.6-2.4:1), extraction solvent ethanol 96% (v/v) j) Liquid extract (DER 1:4.5), extraction solvent ammonia solution 10% (m/m) : glycerol 85% (m/m). ethanol 96% (v/v) : water (1.2:25:112:113) k) Dry extract (DER 7-13:1), extraction solvent water l) Comminuted herbal substance Liquid and solid dosage forms for oral use R. Länger R. Länger 7 Westferry Circus Canary Wharf London E14 4HB United Kingdom Telephone +44 (0)20 7418 8400 Facsimile +44 (0)20 7523 7051 E-mail info@ema.europa.eu Website www.ema.europa.eu An agency of the European Union European Medicines Agency, 2014. Reproduction is authorised provided the source is acknowledged.
Table of contents Table of contents... 2 1. Introduction... 4 1.1. Description of the herbal substance(s), herbal preparation(s) or combinations thereof.. 4 1.2. Information about products on the market in the Member States... 5 1.3. Search and assessment methodology... 6 2. Historical data on medicinal use... 6 2.1. Information on period of medicinal use in the Community... 6 2.1.1. Medicinal products... 6 2.1.2. Information from pharmacopoeias and handbooks... 7 2.1.3. Consolidated list of herbal preparations proposed for the monograph... 8 2.2. Information on traditional/current indications and specified substances/preparations... 9 2.2.1. Indications reported for herbal medicinal products containing herbal preparations of Thyme... 9 2.2.2. Indications reported for Thyme in standard literature on phytotherapy... 9 2.2.3. Indications proposed for the monograph... 9 2.3. Specified strength/posology/route of administration/duration of use for relevant preparations and indications... 10 2.3.1. Posology for adolescents, adults and elderly... 10 2.3.1.1. Comminuted herbal substance for tea preparation (herbal preparation L)... 10 2.3.1.2. Herbal preparations... 10 2.3.1.3. Proposed posology for adolescents, adults and elderly... 11 2.3.2. Posology for children... 11 2.3.2.1. Comminuted herbal substance... 11 2.3.2.2. Herbal preparations... 11 2.3.2.3. Proposed posology for children... 14 2.3.3. Evidence regarding the route of administration... 14 2.3.4. Evidence regarding the duration of use... 14 3. Non-Clinical Data... 14 3.1. Overview of available pharmacological data regarding the herbal substance(s), herbal preparation(s) and relevant constituents thereof... 14 3.1.1. Primary Pharmacodynamics... 14 3.1.1.1. Spasmolytic activity... 14 3.1.1.2. Antibacterial, antifungal, antiviral activity... 17 3.1.2. Secondary pharmacodynamics... 18 3.1.3. Safety pharmacology... 20 3.1.4. Pharmacodynamic interactions... 20 3.1.5. Conclusions... 20 3.2. Overview of available pharmacokinetic data regarding the herbal substance(s), herbal preparation(s) and relevant constituents thereof... 20 3.3. Overview of available toxicological data regarding the herbal substance(s)/herbal preparation(s) and constituents thereof... 21 3.3.1. Acute toxicity... 21 3.3.2. Subchronic toxicity... 21 3.3.3. Mutagenicity... 21 3.3.4. Reproduction toxicity, fertility... 22 EMA/HMPC/342334/2013 Page 2/29
3.3.5. Additional data... 22 3.4. Overall conclusions on non-clinical data... 23 4. Clinical Data... 23 4.1. Clinical Pharmacology... 23 4.1.1. Overview of pharmacodynamic data regarding the herbal substance(s)/preparation(s) including data on relevant constituents... 23 4.1.2. Overview of pharmacokinetic data regarding the herbal substance(s)/preparation(s) including data on relevant constituents... 23 4.2. Clinical Efficacy... 23 4.2.1. Dose response studies... 23 4.2.2. Clinical studies (case studies and clinical trials)... 24 4.2.2.1. Clinical trials in indications associated with cough... 24 4.2.2.2. Clinical trials in other indications... 24 4.2.3. Clinical studies in special populations (e.g. elderly and children)... 24 4.3. Overall conclusions on clinical pharmacology and efficacy... 25 5. Clinical Safety/Pharmacovigilance... 25 5.1. Overview of toxicological/safety data from clinical trials in humans... 25 5.2. Patient exposure... 27 5.3. Adverse events and serious adverse events and deaths... 27 5.4. Laboratory findings... 28 5.5. Safety in special populations and situations... 28 5.6. Overall conclusions on clinical safety... 28 6. Overall conclusions... 28 EMA/HMPC/342334/2013 Page 3/29
1. Introduction 1.1. Description of the herbal substance(s), herbal preparation(s) or combinations thereof Herbal substance(s) Thyme, Thymi herba (European Pharmacopoeia) Whole leaves and flowers separated from the previously dried stems of Thymus vulgaris L. or Thymus zygis L. or a mixture of both species. Minimum content of essential oil: 1.2% with minimum 40% thymol + carvacrol. Constituents (Czygan et al., 2004, Hänsel et al., 1994) Essential oil: there are at least 6 chemotypes of Thymus vulgaris (Thompson 2003) with different compositions of the essential oil; only the thymol -type with thymol as predominant compound complies with the definition in the European Pharmacopoeia. The dried herbal substance contains up to 2.5% essential oil; the main components are thymol, carvacrol, p-cymene, γ-terpinene, linalool, β-myrcene, terpinen-4-ol. Some compounds occur partly as glycosides (e.g. p-cymene-9-ol (Takeuchi et al. 2004), Kitajima et al. 2004). No differences in the composition of the essential oil were found between Thymus. zygis subsp. gracilis and subsp. sylvestris (Pérez-Sánchez et al, 2008). Flavonoids: flavones (e.g. apigenin, luteolin, 6-hydroxyluteolin) and their glycosides, methylated flavones (e.g. cirsilineol, eriodictyol, thymonin). The content of luteolin was found to be 1.12 mg/g in the herbal substance, 3.9 mg/g in a dry extract (not specified) and 0.466 mg/g in the liquid extract prepared according to the German Pharmacopoeia (herbal preparation C) (Bazylko & Strzelecka, 2007). Caffeic acid, rosmarinic acid: Total phenolics (calculated as caffeic acid) are best extracted with 60% ethanol (approximately 50 mg / gram plant dry matter), 30% ethanol yields app. 40 mg/g, while extraction with ethanol 96% resulted in 24 mg/g (Chizzola et al., 2008). These findings are in agreement with the results published (Damianova et al., 2008). However, the investigations reveal that the temperature during extraction has considerably more influence on the amount of extracted tannins (only an unselective analytical method was used). An increase in temperature from 20 to 60 (ethanol 50% and 70%) resulted approximately in a triplication of the extracted amount, while increase of the duration of the extraction had only a minor influence. Carbohydrates: up to 8% polysaccharides, approximately 1% free monosaccharides Triterpenes: derivatives of ursolic and oleanolic acid Herbal preparation(s) See section 2.1 Information on period of medicinal use in the Community. Combinations of herbal substance(s) and/or herbal preparation(s) including a description of vitamin(s) and/or mineral(s) as ingredients of traditional combination herbal medicinal products assessed, where applicable. This assessment refers to the use of Thymi herba as single active substance only. EMA/HMPC/342334/2013 Page 4/29
1.2. Information about products on the market in the Member States Regulatory status overview Member State Regulatory Status Comments Austria MA TRAD Other TRAD Other Specify: Belgium MA TRAD Other TRAD Other Specify: Bulgaria MA TRAD Other TRAD Other Specify: Cyprus MA TRAD Other TRAD Other Specify: Czech Republic MA TRAD Other TRAD Other Specify: Only combinations Denmark MA TRAD Other TRAD Other Specify: Only combinations Estonia MA TRAD Other TRAD Other Specify: Only combinations Finland MA TRAD Other TRAD Other Specify: No products France MA TRAD Other TRAD Other Specify: Germany MA TRAD Other TRAD Other Specify: Greece MA TRAD Other TRAD Other Specify: Hungary MA TRAD Other TRAD Other Specify: Iceland MA TRAD Other TRAD Other Specify: Ireland MA TRAD Other TRAD Other Specify: No products Italy MA TRAD Other TRAD Other Specify: No products Latvia MA TRAD Other TRAD Other Specify: Liechtenstein MA TRAD Other TRAD Other Specify: Lithuania MA TRAD Other TRAD Other Specify: Luxemburg MA TRAD Other TRAD Other Specify: Malta MA TRAD Other TRAD Other Specify: The Netherlands MA TRAD Other TRAD Other Specify: Only combinations Norway MA TRAD Other TRAD Other Specify: Poland MA TRAD Other TRAD Other Specify: Portugal MA TRAD Other TRAD Other Specify: Romania MA TRAD Other TRAD Other Specify: Slovak Republic MA TRAD Other TRAD Other Specify: Slovenia MA TRAD Other TRAD Other Specify: Only combinations Spain MA TRAD Other TRAD Other Specify: No products Sweden MA TRAD Other TRAD Other Specify: Only combinations United Kingdom MA TRAD Other TRAD Other Specify: Only combinations MA: Marketing Authorisation TRAD: Traditional Use Registration Other TRAD: Other national Traditional systems of registration Other: If known, it should be specified or otherwise add Not Known This regulatory overview is not legally binding and does not necessarily reflect the legal status of the products in the MSs concerned. EMA/HMPC/342334/2013 Page 5/29
1.3. Search and assessment methodology First assessment 2007: Search in PubMed, search terms Thymus vulgaris, Thymus zygis, Thymol. Handbooks of Pharmacy and Phytotherapy, manual search in the specialised library of the University of Vienna. For revision of the monograph 2013: Search in database Scopus, search terms Thymus vulgaris, Thymus zygis, Thymol. Selection of articles published between 2007 and March 2013. 2. Historical data on medicinal use 2.1. Information on period of medicinal use in the Community 2.1.1. Medicinal products Austria Herbal preparation Since 1 Comminuted herbal substance At least since 1977 2 Liquid extract (DER 1:2-2.5) extraction solvent mixture of ammonia 10% (1 part), glycerol 85% (20 parts), ethanol 90% v/v (70 parts), purified water (109 parts) 2012 3 Dry extract (DER 7-13:1), extraction solvent water 2011 Belgium Herbal preparation 1 Liquid extract (DER 1:2-2.5) extraction solvent mixture of ammonia 10% (1 part), glycerol 85% (20 parts), ethanol 90% v/v (70 parts), purified water (109 parts) Since 2006 Bulgaria Herbal preparation Since 1 Liquid extract (DER 1:2-2.5) extraction solvent mixture of ammonia 10% (1 part), 1997 glycerol 85% (20 parts), ethanol 90% v/v (70 parts), purified water (109 parts) 2 Dry extract (DER 7-13:1), extraction solvent water 2012 Germany Herbal preparation 1 Liquid extract (DER 1:2-2.5) extraction solvent mixture of ammonia 10% (1 part), glycerol 85% (20 parts), ethanol 90% v/v (70 parts), purified water (109 parts) 2 Liquid extract from fresh herb (DER 1:1.5-2.4), extraction solvent water Since 1978 1978 This extract is often referred as expressed juice. However, as the fresh plant material is mixed with hot water and after 15 minutes contact time pressed, the term liquid extract seems more appropriate compared to expressed juice. 3 Dry extract (DER 6-10:1), extraction solvent ethanol 70% v/v 1993 4 Liquid extract (DER 1:1.2-2), extraction solvent ammonia solution 10% (m/m) : glycerol 85% (m/m). ethanol 96% (v/v) : water (1:20:50:130) 1994 5 Dry extract (DER 1.6-2.4:1), extraction solvent ethanol 96% (v/v) 1983 EMA/HMPC/342334/2013 Page 6/29
6 Liquid extract (DER 1:4.5), extraction solvent ammonia solution 10% (m/m) : glycerol 85% (m/m) : ethanol 96% (v/v) : water (1,2:25:112:113) 7 Soft extract (DER 1.7-2.5:1), extraction solvent ammonia solution 10% (m/m) : glycerol 85% (m/m). ethanol 96% (v/v) : water (1:20:70:109) 1978 1989 8 Soft extract (DER 5.5-6.4:1), extraction solvent ethanol 30% (v/v) 1993 9 Soft extract (DER 5-8:1), extraction solvent ethanol 25% (v/v) At least since 1976 Latvia Herbal preparation Since 1 Liquid extract (DER 1:2-2.5) extraction solvent mixture of ammonia 10% (1 part), 1996 glycerol 85% (20 parts), ethanol 90% v/v (70 parts), purified water (109 parts) 2 Dry extract (DER 7-13:1), extraction solvent water 2012 Lithuania Herbal preparation 1 Liquid extract (DER 1:2-2.5) extraction solvent mixture of ammonia 10% (1 part), glycerol 85% (20 parts), ethanol 90% v/v (70 parts), purified water (109 parts) Since 2010 Dry extract (DER 7-13:1), extraction solvent water 2011 Liquid extract (DER 1:1), extraction solvent ethanol 30% (v/v) 2003 Poland Herbal preparation 1 Liquid extract (DER 1:2-2.5) extraction solvent mixture of ammonia 10% (1 part), glycerol 85% (20 parts), ethanol 90% v/v (70 parts), purified water (109 parts) Since Before 1980 2.1.2. Information from pharmacopoeias and handbooks Herbal preparation Reference Since 1 Liquid extract (DER 1:1), extraction solvent ethanol 24% v/v 2 Liquid extract (DER 1:2-2.5) extraction solvent mixture of ammonia 10% (1 part), glycerol 85% (20 parts), ethanol 90% v/v (70 parts), purified water (109 parts) Austrian Pharmacopoeia ÖAB, current edition, monograph unchanged at least from 1960 onwards German Pharmacopoeia DAB, 1968 onwards At least since 1960 1968 3 Liquid extract (DER 1:1.16), extraction solvent glycerol 85% (m/m) + ethanol 25% v/v (0.1:2) 4 Tincture (1:5), extraction solvent ethanol 45% v/v 5 Fluid extract (no information on DER and extraction solvent) Czech Pharmacopoeia 1970 British Herbal Pharmacopoeia 1973 German Commission E 1984 6 Tincture (1:10), extraction solvent ethanol 70% v/v Van Hellemont, 1988; ESCOP(2003) At least since 1973 EMA/HMPC/342334/2013 Page 7/29
2.1.3. Consolidated list of herbal preparations proposed for the monograph a) Liquid extract (DER 1:1), extraction solvent ethanol 24% v/v (Austrian Pharmacopoeia) b) Liquid extract (DER 1:1.16), extraction solvent glycerol 85% (m/m) + ethanol 25% v/v (0.1:2) (Czech Pharmacopoeia) c) Liquid extract (DER 1:2-2.5) extraction solvent mixture of ammonia 10% (1 part), glycerol 85% (20 parts), ethanol 90% v/v (70 parts), purified water (109 parts); A minimum content of phenolic compounds of 0.03% is required. The description of the manufacturing process of this extract has been improved over the years. The tradition of herbal preparations which are manufactured in accordance with the monographs from the DAB 7 onwards can be accepted.(germany: herbal preparation 1) d) Tincture, DER 1:10, extraction solvent ethanol 70% V/V; 1 ml corresponds to 0.1 g herbal substance. (Van Hellemont, 1988, ESCOP 2003) e) Tincture, ratio herbal substance : extraction solvent 1:5 (British Herbal Pharmacopoeia) f) Soft extract (5-7:1), extraction solvent ethanol 25% - 30% (v/v) (Germany: herbal preparations 8 and 9) g) Liquid extract fresh herb (DER 1:1.5-2.4), extraction solvent water (Germany: herbal preparation 2) h) Dry extract (6-10:1), extraction solvent ethanol 70% (v/v) (Germany: herbal preparation 3) i) Dry extract (DER 1,6-2,4:1), extraction solvent ethanol 96% (v/v) (Germany: herbal preparation 5) j) Liquid extract (DER 1:4.5), extraction solvent ammonia solution 10% (m/m) : glycerol 85% (m/m) : ethanol 96% (v/v) : water (1,2:25:112:113) (Germany: herbal preparation 6) k) Dry extract (DER 7-13:1), extraction solvent water Dry residue from the herbal tea. (Registered as THMP according to Dir 2001/83/EC as amended in several member states.) l) Comminuted herbal substance for tea preparation. The comminuted herbal substance is also currently available in solid dosage forms on the market as capsules containing the powder. However, none of the marketed products is documented in medicinal use since at least 30 years. EMA/HMPC/342334/2013 Page 8/29
2.2. Information on traditional/current indications and specified substances/preparations 2.2.1. Indications reported for herbal medicinal products containing herbal preparations of Thyme Austria Belgium Bulgaria Treatment of catarrhs of the upper airways; acute bronchitis; dry cough. Indicated for cooling, sore throats and calms the cough, once the event of a serious illness excluded. Mucolytic and expectorant in cough associated with cold; symptomatic treatment of acute upper respiratory tract, involving dry irritating cough and hoarseness of voice; as expectorant at cough connected with common colds. Germany For the relief of symptoms in coughs and colds with viscous mucilage. Latvia Bronchitis and cough with viscous sputum, and associated hoarseness; expectorant in cough associated with cold. Lithuania Traditional herbal medicinal product used as anexpectorant in cough associated with cold. Poland Traditional herbal medicinal product used as an expectorant for relief of cough associated with cold. 2.2.2. Indications reported for Thyme in standard literature on phytotherapy Respiratory, thoracic and mediastinal disorders Catarrh of the upper respiratory tract, bronchial catarrh ESCOP 2003, Blumenthal et al., 1998, Fintelmann et al., 2002 Symptoms of bronchitis Blumenthal et al., 1998 Cough with spasms Fintelmann et al., 2002 General disorders and administration site conditions Stomatitis ESCOP 2003 Further traditional indications Digestive disorders Czygan et al., 2004 Halitosis ESCOP 2003 2.2.3. Indications proposed for the monograph Based on the traditional medicinal use of Thyme the following indication is proposed for the monograph. Traditional herbal medicinal product used in productive cough associated with cold. The product is a traditional herbal medicinal product for use in the specified indication exclusively based upon longstanding use. EMA/HMPC/342334/2013 Page 9/29
2.3. Specified strength/posology/route of administration/duration of use for relevant preparations and indications 2.3.1. Posology for adolescents, adults and elderly 2.3.1.1. Comminuted herbal substance for tea preparation (herbal preparation L) single dose daily dose ESCOP 2003 1-2 g, several times daily no detailed data published Blumenthal et al.,1988 1-2 g, several times daily no detailed data published Hänsel et al., 1994 1-2 g, several times daily no detailed data published Fintelmann et al., 2002 2 teaspoons (= 2.8 g), several times daily no detailed data published Several times could be interpreted as 3-4 times daily. 2.3.1.2. Herbal preparations single dose daily dose a) Liquid extract (ÖAB) 2 g (ÖAB) 6 g b) Liquid extract (Czech Pharm.) no detailed data published; calculation via DER: 1.2 2.4 ml no detailed data published; calculation via DER: 3.5-9.3 ml c) Liquid extract (DAB 2006) 1.7 ml 5.1-6.8 ml d) Tincture 1:10 40 drops 120 drops (ESCOP 2003) e) Tincture 1:5 2-6 ml 6-18 ml (British Herbal Pharmacopoeia.) f) Soft extract 50 mg 300 mg (according to the dosage of authorised products) g) Expressed juice from fresh herb 10 ml 30 40 ml (according to the dosage of authorised products) h) Dry extract (DER 6-10:1) 75 200 mg 225 600 mg (according to the dosage of authorised products) i) Dry extract (DER 1.6-2.4:1) 135 mg 1-3 x daily (according to the dosage of authorised products) j) Liquid extract (DER 1:4.5) 480-960 mg 1.44 3.84 g (according to the dosage of authorised products) k) Dry extract (DER 7-13:1) Equivalent to 1-2 g herbal substance Equivalent to 3-8 g herbal substance Assessor s comments Liquid extract according to DAB 7 onwards: Traditionally, the particular liquid extract has been used in a low dosage: single dose 1-2 g, daily dose 1-4 g, which is in agreement with the monograph of the German commission E (Blumenthal et al., 1998). The scientific research on this type of extract (Gaedcke, 2004) as well as the improvement of the manufacture, which can be tracked in the editions of the German pharmacopoeia, revealed that the content of some marker compounds is less than could EMA/HMPC/342334/2013 Page 10/29
be assumed from the DER of 1:2-2.5. Therefore the German national competent authority recommended a higher dosage than the traditional one. The proposed posology in this assessment report for this liquid extract has included both the traditional dosage and the higher one, which is based on the DER. 2.3.1.3. Proposed posology for adolescents, adults and elderly single dose daily dose a) Liquid extract (ÖAB) 1-2 ml 3-8 ml b) Liquid extract (Czech Pharm.) 1.2-2.4 ml 3.5-9.3 ml c) Liquid extract (DAB 2006) 1-4 g 1-14 g d) Tincture 1:10 40 drops 120 drops e) Tincture 1:5 2-6 ml 6-18 ml f) Soft extract 50 mg 300 mg g) Expressed juice from fresh herb 10 ml 30-40 ml h) Dry extract (DER 6-10:1) 75-200 mg 225-600 mg i) Dry extract (DER 1.6-2.4:1) 135 mg 135-405 mg j) Liquid extract (DER 1:4.5) 480-960 mg 1.44-3.84 g k) Dry extract (DER 7-13:1) 100-200 mg 300-800 mg l) Comminuted herbal substance for tea preparation 1-2 g 3-8 g 2.3.2. Posology for children 2.3.2.1. Comminuted herbal substance Literature references ESCOP 2003 Dorsch et al., (2002) single dose children up to 1 year: 0.5-1 g children >1-adolescent: 1-2 g children up to 1 year: 0.5-1 g children >1-adolescent: 1-2 g daily dose no detailed data published no detailed data published 2.3.2.2. Herbal preparations Literature references single dose A) Liquid extract (ÖAB) From 4 years: 1-2 g to be calculated as the herbal substance daily dose 1-6 g (Czygan et al., 2004) to be calculated as the herbal substance (ESCOP 2003) All other herbal preparations no detailed data published no detailed data published EMA/HMPC/342334/2013 Page 11/29
Observational studies in children with Thymi herba (reported from the German national competent authority) Studies with the liquid extract type c) according to the German Pharmacopoeia Dethlefsen (1997, not published, data obtained from German national competent authority): Study medication: Preparation containing 16.95% Thyme liquid extract (DAB), 1 ml corresponds to 75 mg herbal substance. Indication: acute upper respiratory tract infection, symptoms of a bronchitis or pertussis Average duration of treatment: 11.1 days age number of children posology single dose liquid extract daily dose liquid extract < 2 years 18 3-4 x 1.25 ml 0.21 ml 0.63-0.84 ml 2-6 years 105 3-4 x 2.5 ml 0.42 ml 1.27-1.68 ml 7-10 years 19 3-4 x 5 ml 0.85 ml 2.54-3.39 ml Schlaps (1997, not published, data obtained from German national competent authority): Study medication: Preparation containing 49.67% Thyme liquid extract (DAB); 1 ml corresponds to 0.22 g herbal substance. Indication: acute upper respiratory tract infection, symptoms of bronchitis Average duration of treatment: 9.57 days age number of children posology single dose liquid extract daily dose liquid extract < 2 years 48 3 x 1.2 ml 0.6 ml 1.8 ml 2-4 years 121 3 x 1.5 ml 0.75 ml 2.25 ml 4-6 years 123 3 x 1.7-2.0 ml 0.84-1.0 ml 2.53-3.0 ml 6-8 years 68 3 x 2.0 ml 1.0 ml 3.0 ml 8-12 years 77 3 x 2.0-2.3 ml 1.0-1.14 ml 3.0-3.4 ml 12-16 years 9 3 x 2.7-3.0 ml 1.3-1.5 ml 4.0-4.5 ml Graubaum (2004, not published, data obtained from German national competent authority): Study medication: Preparation containing 9% Thyme liquid extract (DAB 2006), 1 ml corresponds to 50 mg herbal substance. Indication: acute upper respiratory tract infection, symptoms of bronchitis Average duration of treatment: 8.8 days age number of children posology single dose liquid extract daily dose liquid extract 1-5 years 171 2-3 x 10 ml 0.9 ml 1.8-2.7 ml 6-11 years 80 3 x 15ml 1.35 ml 4.05 ml EMA/HMPC/342334/2013 Page 12/29
Kaas (2003): Study medication: Preparation containing 8% Thyme liquid extract (DAB), 1 ml corresponds to 40 mg herbal substance. Indication: acute upper respiratory tract infection, symptoms of bronchitis Maximum duration of treatment: 14 days. 100 children in the age between 1 and 16 years. age posology single dose liquid extract daily dose liquid extract <6 years 2.5 ml every 3 hours 0.2 ml 0.6-1.2 ml 6-12 years 5 ml every 3 hours 0.4 ml 1.2-2.4 ml >12 years 10 ml 3-6 times daily 0.8 ml 2.4-4.8 ml Dentinox (Integrierter Abschlussbericht vom 4.12.1997 für Dentinox Gesellschaft KG, Berlin, cited in ESCOP 2003) In an open, multicentre study, 154 children aged 2 months to 14 years (mean 4.4 years) with bronchial catarrh or bronchitis were treated daily with 15 30 ml of Thyme syrup, containing 97.6 mg of Thyme liquid extract (DAB) per ml, for a period of 7-14 days (mean 7.9 days); 46 patients did not receive any co-medication. Compared to the start of the treatment an improvement of coughing was reported in 93.5% of patients. Study medication: Syrup containing 10% Thyme liquid extract (DAB), 1 ml corresponds to 220 mg herbal substance. Indication: bronchial catarrh, symptoms of bronchitis Average duration of treatment: 7.9 days age number of children posology single dose herbal substance daily dose herbal substance 2 months 14 years 154 15-30 ml daily 1.5-3.0 ml Assessor s comment This herbal medicinal product contains the liquid extract according DAB. Therefore it may be concluded that the DER mentioned in the ESCOP monograph should be corrected to 1:2-2.5. Study with the liquid extract from fresh herb expressed juice type g) PädiSolvan (2001, not published, data obtained from German national competent authority) Study medication: Preparation containing 75% expressed juice from fresh herb, 1 ml corresponds to 1.1 g herbal substance. Indication: acute upper respiratory tract infection, symptoms of bronchitis Duration of treatment: 9-12 days age number of children posology single dose liquid extract daily dose liquid extract < 1 years 32 2 x 5 ml 3.75 ml 7 ml 1-4 years 34 2-3 x 5 ml 3.75 ml 7-10 ml 4-10 years 37 2 x 10 ml 7 ml 14 ml 10-12 years 28 3 x 10 ml 7 ml 21 ml EMA/HMPC/342334/2013 Page 13/29
Studies with combination products There are several studies published on combinations of Thyme with other expectorants in children (Ismail et al., 2003; Nauert et al., 2006; Fasse et al., 2006; Schmidt, 2008). Assessor s comments on posology in children Although numerous clinical trials provide evidence on the safe use of the liquid extract (DAB) and the expressed juice, the treatment of cough in children below 4 years of age needs supervision by a doctor. Furthermore, since traditional herbal medicinal products are intended to be used without medical supervision the oral use of Thyme preparations should be restricted to children over 4 years of age. 2.3.2.3. Proposed posology for children Data from observational trials refer only to the liquid extract type c (DAB 2006) and to the liquid extract (= expressed juice, herbal preparation type g). The lower limit of age should be set to 4 years. Children 4-12 years of age: c) Liquid extract: Single dose: 0.5-0.9 ml Daily dose: 2.5-4 ml, divided into 3-5 single doses. g) Liquid extract from fresh herb: Single dose: 7-10 ml, 2-3 times daily As a general precaution ethanol-free preparations should be preferred for children. 2.3.3. Evidence regarding the route of administration The oral administration is the only route of administration for Thyme herb preparations in the traditional indications discussed in this assessment report. 2.3.4. Evidence regarding the duration of use No restriction on the duration of use has been reported for Thymi herba and herbal preparations. The duration of use in clinical studies and observational studies was up to 14 days. However, in these studies the use was under medical supervision. Without medical supervision the duration of use should be restricted to 1 week. 3. Non-Clinical Data 3.1. Overview of available pharmacological data regarding the herbal substance(s), herbal preparation(s) and relevant constituents thereof 3.1.1. Primary Pharmacodynamics 3.1.1.1. Spasmolytic activity In-vitro data Extracts A soft extract (DER 1.7-2.5:1, extraction solvent ammonia solution 10% + glycerol 85% + ethanol 90% + water 1:20:70:109) was examined with regard to the endothelin-induced contraction in the rat EMA/HMPC/342334/2013 Page 14/29
trachea (Engelbertz et al., 2008). Thyme extract reduced dose-dependently in the range 2-10 mg/ml the response to endothelin. Bosentan, an endothelin receptor antagonist acted as a competitive inhibitor. An ethanolic extract (DER 1:2 according to the Belgian Pharmacopoeia V, extraction solvent ethanol 25%, no indication whether v/v or m/m), exhibited in concentrations of 0.133 and 0.266 ml/20 ml spasmolytic activity in the guinea-pig ileum and trachea in a dose dependent manner (Van den Broucke et al., 1980, 1981, 1982). The Thyme extracts were found to be a non-competitive antagonist to specific agonists (acetylcholine, histamine, noradrenaline) and unspecific agonists (barium chloride). Inhibition of calcium-induced contractions on potassium depolarised smooth muscles suggests inhibition of availability of calcium for muscle contraction. An ethanolic extract (ethanol 70%, DER not mentioned, content of thymol 0.072%, carvacrol 0.005%) of Thymi herba exhibited in concentrations between 0.2 and 2.0% v/v in the organ bath dose dependently, a antispasmodic activity on the isolated guinea-pig trachea (spasmogens: BaCl 2, carbachol, histamine, PGF 2a) (Meister et al., 1999). A soft extract (DER 1.7-2.5:1, extraction solvent ammonia solution 10% (m/m): glycerol 85% (m/m): ethanol 90% (v/v): water (1:20:70:109)) was tested on the effect on B2-receptors and mucociliary clearance (Wienkötter et al., 2007). The authors conclude that there is evidence for an influence of the Thyme extract on B2-receptors by both binding studies and biological effects. Aqueous extracts of Thymus vulgaris (macerate and extract of 50 g herbal substance in 300 ml water, final concentration 10% herbal substance) were also tested in pre-contracted tracheal chains of the guinea-pig. The Thyme extracts showed dose dependently (0.25-1% in the test solution) relaxant effects which were similar to those of theophylline (in concentrations from 0.25-1 mm) (Boskabady et al., 2006). A methanolic extract (no data on the DER and strength of the extraction solvent) was tested for its spasmolytic properties on the isolated guinea-pig ileum (Babaei et al., 2008). The extract induced dose-dependently a depression of contractions evoked by field stimulation. The EC 50 was calculated with 1.7 mg/ml. The effect could be inhibited by addition of granisetrone (a 5-HT3-antagonist). Begrow et al., 2010 compared liquid Thyme extracts prepared according to the German pharmacopoeia (liquid extract (DER 1:2-2.5) extraction solvent mixture of ammonia 10% (1 part), glycerol 85% (20 parts), ethanol 90% v/v (70 parts), purified water (109 parts)) and dry extracts either obtained from the DAB extract or by extraction with hot water. The liquid extract contained 0.038% thymol, a spissum extract obtained from this liquid extract contained 0.15% thymol, while in both dry extracts the thymol content was below the detection limit (<0.005%). The concentration of the Thyme extracts was fixed to 100 µg/ml. Extracts with very low thymol contents were effective in all models used except acetylcholine-induced rat ileum contraction. When Thyme extracts with thymol content according to the German Pharmacopoeia or with very low thymol content were compared, the extract with normal thymol content was more effective, both as a relaxant (rat ileum) and as an antispasmodic compound (rat trachea contraction induced by either acetylcholine, Ba ++ or K + ) and in ciliary transport experiments. Thyme extracts with very low thymol content (practically free of volatile oil) were equally effective with respect to endothelin effects. When an extract with very low thymol content had been spiked with increasing concentrations of thymol, a concentration-dependent increase concerning the antispasmodic effect (Ba ++ -induced trachea contraction) was observed. Engelbertz et al., 2012 investigated the antispasmodic effects of thymol-deprived extracts. A liquid extract according to the German Pharmacopoeia was prepared (DER 1:2-2.5) extraction solvent mixture of ammonia 10% (1 part), glycerol 85% (20 parts), ethanol 90% v/v (70 parts), purified water (109 parts), after removal of a part of the extraction solvent a spissum extract remained. This extract contained 96 µg/g thymol and 41 mg/g flavonoids with luteolin-7-o-glycoside as major compound. A bioassay-guided EMA/HMPC/342334/2013 Page 15/29
fractionation revealed that mainly luteolin contributes to the antispasmofic effects (-12% at 2 mg/ml; - 37.1% at 10 mg/ml related to the precontracted trachea), while rosmarinic acid and apigenin do not. Essential oil Thyme oil shows a spasmolytic effect on the smooth muscle and a contracture involving a direct action on skeletal muscle by an unknown mechanism. The essential oils were diluted in methanol to give a final bath concentration of 5x10-5 and 2x10-4 g/ml for rat diaphragm in-vitro with muscle stimulated directly or via phrenic nerve and 4x10-6 -8x10-5 g/ml for field-stimulated guinea-pig ileum studies (Lis- Balchin & Hart, 1997). Isolated substances Isolated thymol was examined with regard to the endothelin-induced contraction in the rat trachea (Engelbertz et al., 2008). Thymol was not effective. Bosentan, an endothelin receptor antagonist acted as a competitive inhibitor. Van den Broucke et al., 1980, 1982, 1983 focussed in several publications on flavonoids. Isolated flavonoids (thymonin, cirsilineol, luteolin and 8-methoxy-cirsilineol) exhibited in concentrations between 0.3 and 100 x 10-6 M spasmolytic activity in the guinea-pig ileum and trachea in a dose dependent manner. The flavones were found to be non-competitive antagonists to specific agonists (acetylcholine, histamine, noradrenaline) and unspecific agonists (barium chloride). Inhibition of calcium-induced contractions on potassium depolarised smooth muscles suggests inhibition of availability of calcium for muscle contraction. Flavones induce relaxation of the carbachol contracted tracheal strip without stimulation of the beta adrenoceptors. The tracheal relaxing effect of the flavones (pd 2 value) was about 3 decades less than that of the beta- adrenergic agonist isoprenaline. Begrow et al., 2010 investigated isolated compounds thymol and carvacrol. They had a concentrationdependent antispasmodic effect in the rat trachea either being stimulated by acetylcholine, K + or Ba ++ (concentrations of thymol 19.1 191 µg/ml, carvacrol 33-330 µg/ml). Thymol at 191 µg/ml suppresses the effect of BaCl2 in the concentration range 5-15 mm. The authors concluded that in various models of antispasmodic effect (ileum and trachea) and by measuring ciliary activity, thymol and carvacrol were active, although other not identified components of Thyme extract appear to be very important as well, since extracts with very low thymol contents are also active. Thymol has in-vitro an agonistic effect on α 1 -, α 2 - and β-adrenoreceptors; the spasmolytic activity was detectable in concentrations >10-6 M. In a concentration of 10-4 M, thymol suppressed the spontaneous contractile activity of the non-striated muscles of the stomach of the guinea-pig. In higher concentrations thymol exhibits a spasmolytic activity in the ratio of 1:10 compared to papaverine (Beer et al., 2007). In-vivo data Begrow et al., 2010 compared liquid Thyme extracts prepared according to the German pharmacopoeia (liquid extract (DER 1:2-2.5) extraction solvent mixture of ammonia 10% (1 part), glycerol 85% (20 parts), ethanol 90% V/V (70 parts), purified water (109 parts)) and dry extracts either obtained from the DAB extract or by extraction with hot water. The liquid extract contained 0.038% thymol, a spissum extract obtained from this liquid extract contained 0.15% thymol, while in both dry extracts the thymol content was below the detection limit (<0.005%) and investigated also the isolated compounds thymol and carvacrol. The extracts were given intragastrally at doses of 0.4 and 4.0 ml/kg to female Wistar rats. When Thyme extracts with normal thymol contents or with very low thymol contents were compared, the extract with normal thymol contents was more effective in ciliary transport experiments. EMA/HMPC/342334/2013 Page 16/29
Assessor s comment The concentrations of extracts and isolated constituents used in these experiments are too high to be considered of relevance to the mechanism of action when used in humans. 3.1.1.2. Antibacterial, antifungal, antiviral activity Extracts In a screening of the activity of plant extracts against Clotrimazole-resistant Candida albicans the methanolic extract from Thymus vulgaris exhibited highest activity with a MIC of 0.62 mg/ml (Inouye et al., 2001). An aqueous extract of Thyme (40 g soaked for 1 hour in 100 ml hot water) exhibited in concentrations of 5%, 10% and 20% a dose dependent inhibition of the adhesion of Streptococcus mutans to human buccal epithelial cells (Hammad et al., 2007). Extracts prepared with ethanol 20% and ethanol 80% (DER 1:24) were investigated on the impact on the Herpes virus infectivity in cell cultures (Reichling et al., 2008). Rosmarinic acid as one of the presumed active ingredients could not be detected in the Thyme extract prepared with ethanol 20%. Both extracts were effective in the plaque reduction assay on acyclovir sensitive and acyclovir resistant virus strains. The IC 50 was determined with 0.34 µg/ml (extract ethanol 80%) and 0.15 µg/ml (extract ethanol 20%). Essential oil The essential oil is antibacterial and antifungal, when tested on Gram-positive and Gram-negative bacteria, fungi, and yeasts, e.g. Candida albicans. The activity is mainly attributed to thymol and carvacrol (Simeon de Bouchberg et al., 1976; Janssen et al., 1986; Menghini et al., 1987; Patakova et al., 1974; Allegrini et al., 1972; Janssen, 1989; Farag et al., 1986; Lens-Lisbonne et al., 1987; Vampa et al., 1988; Chalchat et al., 1991; Giordani, 2004; Fabio et al,. 2007; Sokovic et al., 2008; Das Neves et al,. 2009). Oils with higher percentage of phenolic compounds show higher inhibitory activity (Penalver et al., 2005). Even the vapour of Thyme essential oil (3-12 mg/l air) is highly effective against respiratory tract pathogens (Inouye et al., 2001). Thyme essential oil was also found to act against Methicillin resistant Staphyloccus aureus (MIC 18.50 µg/ml)(tohidpour et al., 2010) and to several multidrug resistant bacterial strains isolated from patients from hospital environment (Sienkiewicz et al., 2012). Correlations between concentrations of thymol and MIC and minimal bactericidal concentration suggest that the formation of membrane perforations is the principal mode of action of thymol against oral bacteria (Shapiro et al., 1995). The components of the essential oil act in an additive way, only with Klebsiella pneumoniae a partial synergism was observed (Iten et al., 2009). In concentrations ranging from 0.08 to 0.16 µl/ml the essential oil from Thymus zygis subsp. sylvestris exhibited strong antifungal activity and was found to be not cytotoxic in skin dendritic cells (Gonçalves et al., 2010). Móricz et al., 2012 identified thymol, carvacrol, (-)-linalool and a-terpineol as compounds mainly responsible for the antimicrobial effect. Tullio et al. 2012 investigated the effect of Thyme essential oil (not meeting the chromatographic profile according to the European Pharmacopoeia) on intracellular Candida albicans. At subminimal/minimal inhibitory concentrations (MIC 0.5% v/v) this essential oil significantly enhanced the intracellular killing activity by human polymorphonuclear granulocytes against Candida albicans, the effect was comparable to the positive control fluconazole (MIC 8 µg/ml). In an in-vitro killing assay without human polymorphonuclear granulocytes a progressive growth of the yeast cells at similar concentrations of Thyme essential oil was observed. EMA/HMPC/342334/2013 Page 17/29
The combination of Thyme essential oil with amphotericin B indicated antagonistic profiles when tested against Candida albicans. The authors conclude that combinations of essential oils and antibiotics should be used with caution (Van Vuuren et al., 2009). Braga et al., 2007 found that a combination of thymol and eugenol acts synergistically on the alteration of the envelope of Candida albicans indicating potential benefits of the combination for the inhibition of C. albicans colonisation. Thyme essential oil exhibited significant dose-dependent antiviral effects against Herpes simplex virus I (Astani et al., 2010). The remaining infectivity was found between 81.6% of the control for a concentration of 1 µg/ml essential oil and 1.0% of the control for a concentration of 50 µg/ml. The authors found that the entire essential oil is more effective with lower cytotoxicity compared to isolated compounds of the essential oil. The inhibitory concentration (IC 50 ) of the essential oil against herpes simplex virus type 2 in-vitro was 0.007%. Plaque formation was significantly reduced by more than 90% when the virus was preincubated with Thyme oil (Koch et al., 2008). Assessor s comment Data regarding the actual content of the essential oil in the herbal preparations and the finished products as well as the concentration in relevant organs after oral use is limited; the therapeutic significance of these findings cannot therefore be estimated. 3.1.2. Secondary pharmacodynamics In-vitro data for extracts, the essential oil and isolated substances Many compounds from the leaves of Thymus vulgaris (e.g. Rosmarinic acid, eriodictyol, taxifolin, luteolin, p-cymene, thymol, carvacrol) showed radical scavenging properties (Haraguchi et al., 1996, Dapkevicius et al., 2002). In a model using CCl 4 -induced hepatotoxicity the essential oil of Thymus zygis (thymol-type) showed a notable activity combined with a marked scavenger activity (Jimenez et al., 1993). Thyme ethanolic extracts and the essential oil exhibit antioxidant activity (Chizzola et al., 2008). Extracts prepared with ethanol 30% and 60% showed a considerable higher antioxidant activity in the DPPH assay as well as in the Fe-reduction assay compared to an extract prepared with ethanol 90%. The antioxidant activity of the extracts correlates with the content of rosmarinic acid, while for the antioxidant activity of the essential oil mainly depend on the content of phenolic compounds like thymol and carvacrol. DPPH radical scavenging activity of Thyme tea was less compared to green tea and peppermint tea, but higher than e.g. olive leaves or sage leaves (Büyükbalci & El, 2008). Behnia et al., 2008 investigated the antiamebic effect of a hexane extract (DER 29:1), an extract prepared with ethanol 90% (DER 9.5:1) and of the essential oil. Minimal inhibitory concentrations against the trophozoites of Entamoeba histolytica were established with 4 mg/ml, 4 mg/ml and 0.7 mg/ml respectively. Thymol in concentrations of 2.5-20 µg/ml was shown to inhibit the experimentally induced release of neutrophil elastase. The authors concluded that thymol may have a helpful effect in the control of inflammatory processes present in many infections (Braga et al., 2006). Ocaña & Reglero, 2012 concluded that thymol dose-dependently contributes to anti-inflammatory effects. Extracts obtained with supercritical CO 2 significantly reduced production and gene expression of the proinflammatory mediators TNF- α, IL-1B and IL-6 and increased these parameters in IL-10 in human macrophages in doses between 5 and 25 µg/ml. EMA/HMPC/342334/2013 Page 18/29
Thyme oil inhibits prostaglandin biosynthesis (Wagner et al., 1986). Rosmarinic acid has antiinflammatory activity due to inhibition of classical complement pathway in rats and inhibition of some human PMN functions, when tested at several dosage levels and by several application methods invitro (e.g. Englberger et al. 1988: 0.316-3.16 mg/kg i.m. in the rat paw oedema model; Gracza et al., 1985: IC 50 of 3.37 mm in the model of inhibition of the malondialdehyde formation in human platelets) Rosmarinic acid in concentrations up to 200 µm shows a strong antiangiogenic potential, which might be related to its anti-oxidative activity, which further resulted in the inhibition of ROS (reactive oxygen species) - associated VEGF (vascular endothelial growth factor) expression and IL-8 release (Huang et al., 2006). Rosmarinic acid exhibited also antiapoptotic effects on H 2 O 2 induced cell injury in concentrations of 10 and 40 µm (Gao et al., 2005). Thymol is a positive allosteric modulator of the GABA(A) receptor; it enhances the GABA-induced chloride influx at concentrations lower than those exhibiting direct activity in the absence of GABA (EC 50 = 12 µm and 135 µm respectively)(garcia et al., 2006). The essential oil of Thymus zygis showed acetylcholinesterase inhibition capacity with a IC 50 = 1.1 µg/ml (Dandlen et al., 2011). A hexane extract from Thymus vulgaris inhibited the mitogen stimulated proliferation of lymphocytes (Amirghofran et al., 2011,). Thymol was found to be responsible for this effect. A water extract of a defatted Thyme (DER app. 22:1) showed in concentrations up to 50 µg/ml immunoinhibtory effects on mitogenic and allogenic T cell proliferation (Amirghofran et al., 2012). Carvacrol as isolated compound induces apoptosis in HepG2 cells in concentrations starting from 0.05 mmol/l) by direct activation of the mitochondrial pathway (Yin et al., 2012). In-vivo data for extracts, the essential oil and isolated substances An ethanolic extract of Thyme (no detailed information available) was applied topically 2 times daily for 6 weeks in Balb/c mice with artificial leishmaniasis (Hejazi et al., 2009). The lesions improved significantly better compared to placebo. A dry extract (extraction solvent methanol 28%) exhibited a dose dependent anti-nociceptive effect after intraperitoneal injection (100 1000 mg/kg) (Taherian et al., 2009). Rosmarinic acid exhibited inhibitory activity in three in-vivo models in which complement activation plays a role: Reduction of oedema induced by cobra venom factor in the rat; inhibition of passive cutaneous anaphylaxis; impairment of in-vivo activation by heat-killed Corynebacterium parvum of mouse macrophages. Rosmarinic acid did not inhibit t-butylhydroperoxide-induced paw oedema in rat, indicating selectivity for complement-dependent processes (Englberger et al., 1988). Fachini-Queiroz et al., 2012 investigated the anti-inflammatory activity of Thyme essential oil, thymol and carvacrol in the models of ear oedema in mice, induced pleurisy in rats and in-vitro chemotaxis. High concentrations of the essential oil (up from 250 mg/kg) as well as of carvacrol (up from 100 mg/kg) could reduce the exsudate volume induced by carrageenan. 10 mg carvacrol per ear could reduce the ear oedema. However, higher concentrations as well as thymol was inactive in this model. A diet containing Thyme (up to 2%) as well as oral thymol and carvacrol (200 mg/kg) given once a day over 7 days induced the activity of phase I and phase II enzymes in the mouse liver up to 90% (Sasaki et al., 2005). Five thousand ppm Thyme essential oil in the diet of Balb/c mice caused a significant reduction in macroscopic and microscopic colitis scores in TNBS colitis as well as a decrease in induced paw oedema EMA/HMPC/342334/2013 Page 19/29
and ear swelling. However, in lower concentration (1250 ppm) an increase in the ear oedema was observed (Juhás et al., 2008) A water extract (30 g Thyme macerated in 60 ml water for one day, administered to mice with 500 mg/kg b.w. for 14 days) was able to alleviate increased levels of several liver enzymes due to alcohol intake (Shati & Elsaid, 2009). Thymol and carvacrol are potent insect repellents in concentrations of about 0.05% in topical treatment (Choi et al., 2002; Park et al., 2005). Abd el Kader & Mohamed, 2012 investigated the protective effects of a hot water extract of Thyme against symptoms of liver and renal toxicity induced by paracetamol in rats. Administration of 500 mg/kg b.w. of the freeze dried extract could significantly improve altered enzyme levels as well as the histological architecture of liver and kidney. A lyophilised decoction of Thyme was administered orally in doses of 100 mg/kg to rats with induced hypertension over a period of 8 weeks (Kensara et al., 2012). The blood pressure could be lowered to nearly the initial values (control 136 mmhg; untreated 186 mmhg; treated 138 mmhg). Additionally the altered renal tissue could be improved by the Thyme extract. 3.1.3. Safety pharmacology No information available. 3.1.4. Pharmacodynamic interactions No information available. 3.1.5. Conclusions The results from non-clinical experimental studies on Thymi herba and preparations thereof to support the proposed indications are very limited. Most effects observed in pharmacological studies were obtained in concentrations higher than expected when the herbal preparations are used and administered in the traditional way. The reported pharmacological effects are not considered contradictory to the traditional uses. 3.2. Overview of available pharmacokinetic data regarding the herbal substance(s), herbal preparation(s) and relevant constituents thereof Absorption, Distribution, Metabolism, Elimination Extracts No data available Rosmarinic acid After oral administration of rosmarinic acid (50 mg/kg rat) the peak concentration is reached within 0.5 hours. Rosmarinic acid is present in plasma as conjugate or in the methylated form. The main metabolites are free or glucuronide conjugates. Orally administered rosmarinic acid is also degraded to caffeic acid, ferulic acid and m-coumaric acid, the majority of these degradation products is eliminated within 8 hours after oral administration (Baba et al., 2004). EMA/HMPC/342334/2013 Page 20/29